Electric water heater



A. V. LIVINGSTON ELECTRIC WATER HEATER Feb. 10. 1925.

Filed Feb; 2, 1922 ap v 4 INVENTOR Patented Feb. 10, 1925.

UNITED STATES PATENT OFFICE ALAN VARLEY LIVINGSTON, 013 NEW HAVEN,CONNECTICUT, KSSIGNOR TO THE SAFETY GAR HEATING & LIGHTING COMPANY, ACORPORATION OF NEW JERSEY.

ELECTRIC WATER HEATER.

Application filed Februa'ry 2, 1922.

To all whom 2'2. may concern:

Be it known that I, ALAN VARLEY LIV- mesrozv, a citizen of the UnitedStates, and a resident of New Haven, in the county of New Haven andState of Connecticut, have invented an Improvement in Electric lVaterHeaters, of which the following is a specification.

This invention relates to electric heaters for water, and with regard toits more specific features this invention relates to heaters of theabove nature in which water is automatically heated as required.

One of the objects of this invention is to provide apractical apparatusof the above nature of thoroughly dependable action. Another object isto provide apparatus of the above nature in which the heating cur rentis economically used and in which the chances of injury to the severalparts there of, as by overheating, are reduced to a mini mum. Anotherobject is to provide appara tus of the above character of simple and yetdurable and compact construction. Other objects will be in part obviousor in part pointed out hereinafter.

In the accompanying drawings in which is shown one of various possibleembodiments of this invention,

Figure 1 is vertical central crosssection of an electric water heater;

Figure 2 is a crosssection taken on the line 22 of Fig. 1 showing theswitch construction for controlling the heating current, the parts beingshown in the off position; and

Figure 3 is a similar view showing the several parts in the on position.

Figure 4 is a plan view showing a. part in detail of a portion of theapparatus of Fig. 1.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

The invention accordingly consists in the features of construction,combination of ele ments, and arrangement of parts as will be Serial No.533,625.

exemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following shapehaving detachably secured thereto at its upper end an end housing 11provided with a nipple 12 to which connection may be made to a suitablesource of water supply. The main casing 10 is provioed adjacent itsupper end with a transversely extending dividing partition or wallmember 13 having preferably f rined integrally therewith a downwardlyextending and substantially centrally positioned post or stem 14. Thewall member 13 is adapted to cooperate with a diaphragm 15 preferably ofmetallic construction and mounted at the lower end of the main casing 10so as to form between the wall member 13 and the diaphragm 15 asubstantially enclosed compartment in which I prefer to mount theelectric circuit controlling devices hereinafter more clearly described.

A pair of conduits 16 and 17 are in fluidtight connection with suitableopenings in the wall member 13 and the diaphragm 15 to provide suitablefluid passage through the water-tight housing above described and in thewall member 13 and adjacent the upper ends of the conduits 16 and 17there are formed the valve seats 1i and 19 respectively and preferablyof conical shape. Associated with the valve seats 18 and 19 respectivelyare the valve members 20 and 21 adapted to control the passage of waterthrough the conduits 16 and 17. The valve members 20 and 21 arecontrolled by the valve stems and 23 respectively extending preferablydownwardly through the respective conduits and beyond the diaphragm 15where they are supported in the respective ends of a yoke 24. The endsof the valve stems 22 and 23 extend through suitable openings in therespective ends of the yoke 52% and are provided with collars 26 and 27respectively integrally mounted thereon so that a downward pressure uponthe valve members 20 and 21 due to the water pressure acting thereonwill be transmittedto the yoke 24.

The valve members 20 and 21 are operated or moved in an upward directionto permit the flow of water through the conduits 16 and 17 respectivelyby means of suitable cams acting upon the lower ends of the valve stems22 and 23 respectively. One of these cams 25 is clearly shown in Fig. 1in operative relation to the valve stem 22, and the cam 25, togetherwith the cam acting upon the valve stem 23, is integrally formed with aring member 28 flanged as at 29 so as to overlap the main cylindricalcasing 10, thereby to be relatively rotatable with respect to the maincasing 10. A handle 30 is mounted upon the exterior of the ring member28 to permit manual operation thereof. The ring member 28 is held inrotatable and fluid-tight connection with the main casing 10 by means ofthe cylindrical housing member 31 which is seated at its upper endagainst the ring member 28 by means of the flange 32 andwhich is rigidlypositioned with respect to the main casing 10 by meamz of the end cap 33mounted upon the lower end of the supporting stem 14 and conveniently inthreaded engagement therewith as at 34. The ring member 28, forming partof the entire housing is thus rotatably mounted and in fluid-tightconnection with its as sociated members and may conveniently be manuallyoperated to place the valve members 20 and 21 in open position.

The ring member 28 is provided with suitable openings as at 35 to permitthe flow of water in a general downward direction into the housing 31 inwhich is mounted the electric heating unit. The heating unit preferablycomprises a substantially cylindrical and hollow core 36 of suitableinsulating material having disposed upon its interior and exteriorsurfaces a suitable resistance element. Thus, as is clearly shown inFig. 1, theresistance element may comprise a winding 37 of a suitableresistance wire wound upon the exterior of the core 36 and a secondwinding 38 positioned and suitably mounted upon the interior surface ofthe core 36. The wire or metal forming the resistance element of theheating unit is preferably nickle-plated so as to be immune fromcorrosive action of the water. The ends of the windings 37 and 38 arerespectively connected to suitable terminals 39 and 40 preferably ofheavy construction and suitably slotted so that they may be engaged bysuitable binding posts indicated generally at 41 and 42 respectivelymounted in the walls of the housing 31 preferably at the upper endthereof and suitably insulated therefrom.

At the upper end of the core 36 of the heating unit there is mounted aring shaped member 43 suitably serrated throughout its periphery so asto contact with the interior walls of the housing 31 and to maintain thecore 36 in substantial alignment therewith, it being understood that thecore 36 has an outside diameter materially less than the inside diameterof the housing 31 so as to provide a substantially annular path of flowfor water therebetween. The lower end of the core 36 is substantiallycentered with respect to the housing 31 by means of a plurality ofprojections 44 (Fig. 4) suitably spaced from one another and adapted tomaintain the end of the core 36 out of contact with the bottom surfaceof the cap 33. The annular passage exterior of the core 36 and theinterior passage through the inside of the core 36 are thus placed incommunication with one another by the end cap construction abovedescribed. The cap 33 is threaded into the housing 31 so that theheating unit, the housing 31 and the cap 33 may be first assembled as anentire unit and may thereupon be assembled with relation to the maincasing 10 and the ring member 28 by threading the cap 33 upon the mainsupporting stem 14. Before mounting the heating unit with its associatedhousing upon the stem 14, however, the assembled parts are firstpreferably dipped in a suitable insulating compound, such as bakelite orenamel for example, thereby to insulate the electrical parts from thewater passing in contact therewith.

From the lower part of the housing 31 the path of flow for the water tothe apparatus is continued in an upward direction by means of a suitableconduit preferably taking the form of a tube 45 surrounding thesupporting stem 14 and held in central posipart f th tube 45 to permitthe entry therein of the water and to permit its flow in anupward'direction through the tube 45 and through the discharge spout 48extend ing though the housing 31 and in connection with the tube 45 atits upper end.

Considering now the means for controlling the flow of current to theheating unit. it will first be noted that there is rotatably mounted atthe upper end of the post 14 a sleeve 49 extending upwardly through thediaphragm 15 and into the enclosed compartment formed bythe diaphragm 15and the wall member 13 in the main casing 10. The sleeve 49 has rigidlymounted at its lower end a squared bushing 50 of substantial extent inan axial direction and adaptedto be slidably engaged by the ring member28 which is provided at its central part with Ill a squared opening'51into which the squared bushing 50 loosely fits. The sleeve 4:9 with thesquared bushing 50 may thus partake of an axial movement along the stem14 and throughout such movement will be in driving connection with thering member 28. Thus, as the ring member 28 is rotated by means of thehandle 30 to cause the opening of the valves 20 and 21 hereinbeforedescribed, the sleeve %9 will be rotated therewith. The upper end of thesleeve 49 is squared to provide what may be termed a clutch portion 52(see Fig. 2) adapted to be engaged when in downward position by thesquared opening 53 in the hub member 54 of a switch operating device.The hub member 54 has integrally formed therewith the two arms 55 and 56adapted to support at their outer ends a'ring'member 56 adapted to fitfreely within the cylindrical casing 10. It will thus be seen that withthe squared portion 52 of the sleeve l9 in engagement with the hubmember as shown in Fig. 1, a rotation of the sleeve 49 in response tothe operation of the ring member 28 will bring about a like rotation ofthe ring member 56 within the fluid-tight compartment.

lVithin the conduit l5 and surrounding the stem 1a is a spring 57engaging at its upper end the lower end of the sleeve 49 so as to tendto move the sleeve 49 in an upward direction and to place the squaredportion 52.0ut of engagement with the hub member 5 1. The tendency ofthe spring 57 thus to place the clutchportion 52 in disengaging positionis, however, opposed by the pressure of water upon the valve members 20and 21. As hereinbefore described, the valve members 20 and 21 areadapted to transmit the downward pressure due to the action of waterthereon to the yoke 24 which, as will be seen from Fig. 1, is supportedupon the squared bushing of the sleeve -19. Thus, when water is presentin the upper part of the cylindrical casing 10, the downward action ofthe water upon the valves 20 and 21 is transmitted through the yoke 2ato the sleeve a9 and tends to hold the squared portion 52 of the sleevein engagement with the hub member l Vhen therefore the handle 30 ismanually operated to swing the ring member 28 in a anti-clockwisedirection as viewed in Fig. 2 of the drawings, such rotary motion willbe communicated through the sleeve 49 and the clutch portions 52 and tothe ring member 56 providing, however. that. water is present in theupper part of the casing 10 to maintain the clutch portions inconnection above described. Should no water be present, however, to actupon the valves 20 and 21, the spring 57 is free to act withoutopposition and moves the sleeve 29 along the stem let to raise theclutch portion 52 of the stem t9out of engagement withthe hub member 54.No rotary motion is thus communicated to the ring member 56. A spring 28compressed during the anticlockwise rotation of the ring 28 is effectiveto return ring member 28 to normal valve-closing position.

Referring now more specifically to Fig. 2 of the drawings, it will beseen that the ring member 56 has pivotally secured there to atsubstantially diametrically opposite points two links 58 and 59pivotally cons nected at their inner ends to a yoke member 60 rotatablymounted upon a lower cylindrical extension as of the hub 54 so that theyoke 60 is free to rotate relatively to and underneath the hub member 5iand its associated ring supporting arms and 56. Upon the yoke memberthere are mounted two spring contacts 61 and 63 suitably insulatedtherefrom and interconnected by means of a suitable conductor Get. Thecontacts 61 and 63 are adapted to co-operate with the spring clips 65and 66 respectively mounted upon the interior of the casing 10 andwithin the enclosed compartment therein, suitable binding posts 67 and68 respectively being provided for connecting the clips 65 and 66 to anexterior circuit.

Upon the ring member 56 there are rigidly mounted as by the screws 69and 70 two circumferentially extending guiding bars 71 and 72 upon whichare respectively supported the springs 7 3 and 74. The free ends of theguiding bars 71 and 72 are guided in suitable abutments or posts 75 and76 respectively mounted upon the interior walls of the casing 10, andthese posts also provide suitable abutmentsagainst which the springs 73and 7a may be compressed during counter-clockwise rotation of the ringmem ber 56 as viewed in Fig. 2 of the drawings.

The several parts are normally held in the position shown in Fig. 2- andthe contact springs 61 and 63 are held in the oft position by the actionof the springs 7 7 and 78 surrounding the links 59 and 58 respectively.These springs tending to expand, tend normally to rotate the yoke member60 in a counter-clockwise direction and the latter together with itsassociated spring contacts 61 and 63 is held in the off position bymeans of suitable stops 79 and 80 engaging the conduits 16 and 17respectively.

Vhen the ring member is given a counter-clockwise rotation as abovedescribed, the outer pivotal supporting points 77 and 78 of the links 59and 58 respectively are moved into substantial alignment with the pivotpoints 77 and 78", with which the links 59 and 58 respectively are inslotted connection; and as soon as the outer pivot points are moved toa. position beyond the alignment of these four pivot points, the springs77 and 78, compressed during this action, are at liberty to expand.During such expansion they cause a clockwise rotation of the yoke withits associated contact springs 61 and 63 into the position shown in Fig.8, whereby the contacts 61 and 63 are thrown into engagement with thecontact clips 65 and 66 respectively. The yoke-member 60, in thus beingrotated in clockwise direction is held at the limit of its movement bysuitable stops or abutments 81 and 82 mounted upon the interior of thecasing 10 and adapted to engage the stops or arms 79 and respectively onthe yoke member 60. The yoke member 60 with its associated operatinglinks 58 and 59 forms in effect a toggle acting to bring about a quickand rapid operation of the switch.

The terminals of the heating unit, as well as those of the switch, arepreferably interconnected upon the exterior of the apparatus and thecircuits may, for example, be completed as follows: One side of thecircuit may be connected to the binding post 67 in connection with theclip 65 in the switch and upon closure of the switch as above describedthe circuit is completed through the spring contacts 61 and 63interconnected by means of the conductor 64 to the other binding post68: from this binding post 68 a conductor may lead to the terminal 41upon the exterior of the casing 31 and leading to the resistance elementof the electric heating unit. The other side of the circuit maythereupon be connected to the terminal 42 of the electric heating unit.

During the above described operation of rotating the ring member 28through its handle 30 to operate the valves 20 and 21 and the switch, incase water is present in the casing, the springs 73 and 74 arecompressed and are thereupon eliecti've to re turn the switch to openposition and the valves to closed position as soon as the handle 30 isreleased. Upon such release of the handle 30, the springs 73 and 7 4expand to rotate the ring member 56 in clockwise rotation therebyreversing the operation of the switch as above described and returningthe parts of the switch to off position as shown in Fig. 2. The sametoggle action takes place during the breaking of the electric circuitand the quick and certain action of the switch insures the eliminationof arcing and a consequently great life of the switch. The sameclockwise rotation of the ring member 56 due to the ex pansion of thesprings 73 and 74 is effective also to rotate the sleeve 49 and with thelatter the ring member 28 and handle 30,

thus restoring these parts to normal in as sistance to spring 28 Duringsuch restoration of the ring member 28 to normal the cams 25 arewithdrawn from coaction with the stems 22 and 23 of the valves 20 and21, and the latter are thereupon seated in their stantially annularstreams, thus insuring an intimate contact of the water with the heatingelements of the heating unit. Furthermore, the Water after having passedthe heating unit is conducted in a single upwardly directed passageentirely surrounded by the heating unit so as to bring about a stillfurther interchange of heat. During this upward flow, moreover, thewater is again made to take the form of a. thin annular streamsurrounding the stem 14 and within the conduit 45 so that the heatinterchange is made all the more effective.

It will thus be seen that there has been provided in this invention anelectric heating apparatus of highly etficient and dependable action.The electric heating unit is not only of such construction as toinherently protect it against corrosion and against the effects ofelectrolysis, but is also controlled in such manner that danger fromoverheating and eventual burning out due to the absenoe of water in theapparatus is entirely eliminated. The construction, moreover, is ofmarked simplicity of operation and it will be noted that a complexity ofparts is avoided in arranging the valves for controlling the'flow ofwater through the apparatus to be effective also to control theoperation of the switch in response to the water pressure in the maincasing. Such water pressure, by way of brief rsum, acts upon the valvemembers 20 and 21 to place the clutch portion 52 of the sleeve 49operative in response to the handle 30 in operative connection with theswitch-operating toggle mechanism, and itmay briefly be noted that afterthe initial action of the valves in thus controlling the connection, the

valves may be lifted to permit the flow of water through the apparatus,the friction of the parts, after being once placed in operativeconnection, being sufficient to permit the resultant and completingoperation of the operating switch. Thus, in spite of the fact that, uponthe opening of the valves, the pressure thereon is decreased to asubstantial extent, the clutch portions 52 and 54 are held in operativeconnection by the friction t-herebetween, it being understood that thisconnection operates against the spring of the operating mechanism of theswitch.

It will also be seen that the several parts l (l O of the apparatusprovided in this invention are readily a: d conveniently assembled andthat the construction thus provided is of such nature that ready accessmay be had to the various interior parts of the apparatus. Thus, forexample, replacement or the repair of the several parts may easily bemade.

It may furthermore be noted that there has been provided in thisinvention an ap paratus in which the several objects above noted, aswell as others, are achieved and in which many advantages are attained.

As many possible embodiments might be made of the above invention and asmany changes might be made in the embodiment above set forth or shown inthe accompanying drawing, it is to be understood that all matterhereinbefore set forth is to be interpreted as illustrative and not in alimiting sense.

I claim as my invention:

1. In electrical water-heating apparatus, in combination, meansproviding a path of flow for water, a valve associated therewith forcontrolling the flow of water therethrough, an electric heating unitassociated with said means and in the path of flow therein, a switch forcontrolling the current flow to said unit, a member mounted for manualmovement in one direction, a spring arranged to oppose the manualmovement of said member, and means responsive to manual movement of saidmember arranged to operate either said valve and said switch conjointlyor said valve alone, depending upon the presence or absence,respectively, of water in said path of flow.

2. In electrical water-heating apparatus, in combination, a main casingadapted to form a path of flow for water therethrough and built up of aplurality of contiguous sections, one of which is movable with respectto the other, an electric heating unit within said casing, and meansresponsive to movement of said movable part of said casing forsimultaneously controlling the flow of water past said electric heatingunit and the flow of current to said heating unit.

3. In electrical water-heating apparatus, in combination, a main casingadapted to form a path oi flow for water t-herethrough and built up of aplurality of contiguous sections, one of which is movable with respectto the other, an electric heating unit within said casing, a valve forcontrolling the flow of water through said casing and past said heatingunit, a switch for controlling the flow of current to said heating unit,and means responsive to the movement of said movable part of said casingfor operating either said valve and said switch substantially conjointlyor said valve alone, depending upon the presence or absence respectivelyof water in said path of flow.

4. In electrical water-heating apparatus,

in combination, a casing made up of a plurality of sections and adaptedto provide a path of flow for water, two adjacent sections beingsubstantially concentric and the one rotatable with respect to theother, an electric heating unit within said casin a valve forcontrolling the flow of water past said heating unit, a switch forcontrolling the flow of current to said heating unit, and meansresponsive to a rotary movement of said movable section of said casingfor simultaneously opening said valve and closing said switch.

5. In electrical water-heating apparatus, in combination, a casing madeup of a plurality of sections and adapted to provide a path of flow forwater, two adjacent sections being substantially concentric and the onerotatable with respect to the other, an electric heating unit withinsaid casing, a valve for controlling the flow of water past said heatingunit, a switch for controlling the flow of current to said heating unit,and means responsive to a rotary movement of said casing for operatingeither said valve and said switch substantially conjointly or said valvealone, depending upon the presence or absence of water in the path offlow provided by said casing.

6. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, an electricheating unitmounted in said casing, a valve for controlling the flow of waterthrough said casing, and past said heating-unit, a switch controllingthe flow of current to said heating-unit, toggle means for operatingsaid switch, and means dependent upon the presence or absence of waterin said path of flow for operating substantially conjointly said valveand said toggle means or for operating only said valve, respectively.

7. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, a valve for controllingthe flow of water through said casing, an electric heating-unit mountedin said casing, and adapted to heat water passing through said casing, aswitch for controlling the current to said heating-unit, manuallymovable means for simultaneously opening said valve and closing saidswitch to permit the flow of water through said casing, and of currentto said heating-unit, and automatic means for returning said valve toclosed position and said switch to open position.

8. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, an electricheating-unit mounted in said casing for heating water passingtherethrough, a valve controlling the flow of water through said casing,a switch controlling the flow of current through said heating-unit,"means arranged for manual movement for simultaneously opening saidvalve and closing said switch to permit the fiow of water through saidcasing, and of current to said heatingunit, and a spring for returningsaid valve open position and for operating said switch to close thecircuit to said heating-unit, and connections between said switch, saidmanual'operating means, and said spring for returning said manual meansto normal position said valve to closed position and said switch to openposition.

10. Inelectrical water-heating apparatus, in combination, means forproviding a path of flow for water, an electric heating-unit interposedin said path, manual means for controlling the flow of current to saidheating-unit, and means dependent upon the presence or absence of waterin said path of flow for permitting or preventing, respectively, theoperation of said currentcontrolling means.

11. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, an electricheating-unit mounted in said casing, a switch controlling the flow ofcurrent to said heating-unit, means for operating said switch, a clutchconnecting said switch and said operating means, and means responsive tothe pressure of water in said casing for controlling said clutch.

12. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, an electricheating-unit mounted in said casing, a switch controlling the flow ofcurrent to said heatingunit, means for operating said switch, a clutchconnecting said switch and said operating means, a spring tending tohold said clutch in disengaging position, and means responsive to thepressure of water in said casing, adapted to oppose said spring, and toplace said clutch in engaging position when water is present in saidcasing.

13. In electrical water-heating apparatus, in combination, a casingproviding a path of flow for water therethrough, an electricheating-unit mounted in said casing, a switch for controlling the flowof current to said unit, a clutch member adapted to interlock with saidswitch, a floating valve member for controlling the flow of water insaid casing, connected to said clutch member and adapted to beresponsive to pressure. of water in said casing, thereby to place saidclutch member in interlocking position with said switch, and manualmeans for operating said valve member to permit the flow of waterthrough said casing and for operating said clutch member.

14. In electrical water-heating apparatus, in combination, a casingadapted to form a path of flow for water therethrough, an electricheating-unit mounted in said casing, a switch for controlling the flowof cur rent to said heating-unit, a clutch member adapted to interlockwith and to operate said switch, means tending to hold said clutchmember out of interlocking relation with said switch, a float-ing valvemember for controlling the flow of water through said casing connectedto said clutch member and adapted to be responsive to pressure of waterin said casing, and to oppose said clutch holding means to place saidclutch member-.;-

in interlocking relation with said switch and means for operating saidvalve member and said clutch member.

15. In electrical water-heating apparatus, in combination, a casingadapted to form a path of flow for water therefrom, an electricheating-unit associated with said casing, a switch for controlling theflow of current to said heating-unit, means for op crating said switchto permit the flow of.-

current to said heating-unit, means forming a detachable connectionbetween said operating means and said switch, and a diaphragm associatedwith said casing and responsive to pressure of water in said casing tocontrol the connection between said switch-operating means and saidswitch.

16. In electrical water-heating apparatus, in combination, a. casingadapted to form a path of flow for water therethrough, an

electric heating-unit associated with said casing, a switch forcontrolling the flow of current to said heating-unit, a floating valvehaving a portion adapted to be exposed to water in said casing, wherebysaid floating valve may be acted upon by the pressure of water in saidcasing, means for operat ing said valve to permit the. flow of waterthrough said casing, a detachable connection between said switch andsaid valve-operating means, and means operated by said floating valve inresponse to pressure of water in said casing for controlling saidconnection. 1

17. In electrical water-heating apparatus,

casing, and having a resistance element disposed upon its interior andexterior surlll) faces, and meansto'r mounting said heatingunit within,said casing to form a plurality of paths ot'flow thcrebetween.

18. In electrical water-heating apparatus, in combination, a main casingadapted to form a path of flow for water therethrongh, an electricheating-unit, having a pair of connecting terminals; means tordetachably mounting said unit within said casing, and a pair ofconnecting terminals associated with said casing and positioned to bedetachably engaged by the connecting terminals of said heating unit asthe latter is inserted into said casing.

19. In electrical water-heating apparatus, in combination, a main casingadapted to form a path of flow for water therethrough, an electricheating-unit associated therewith, comprising a main core having aresistance element disposed upon its surface: and means forming anon-corrosive coating for the resistance element in said electricheating-unit.

20. In electrical water-heating apparatus, in combination, a casingadapted to provide a path of flow for water therethrough, an electricheating-unit mounted in said casing and exposed to the water passingthere through, and comprising a core having a resistance elementdisposed upon its surface, and means forming an insulating coating forsaid resistance element of said electric heating-unit.

21. In electrical water-heating apparatus, in-combination, a main casingadapted to form a path of flow for water therethrough, an electricheating-unit having a cylindrical core and a resistance element disposedupon its outer surface: a cylindrical housing having a greater insidediameter than the outside diameter of said core, thereby to form anannular path of flow therebetween: means for mounting said heating-unitwith in said cylindrical housing, and means for detachably connectingsaid cylindrical housing with said main casing.

22. In electrical Water-heating apparatus, in combination, a main casingadapted to form a path of flow for water therethrough, an electricheating-unit having a cylindrical core and a resistance element disposedupon its outer surface; a cylindrical housing having a greater insidediameter than the outside diameter of said core, thereby to form anannular path of flow therebetween; means for mounting said heating-unitwithin said cylindrical housing; a means for detachably connecting saidcylindrical housing With said main casing, and a valve mounted in saidmain casing for controlling the flow of Water therethrough.

23. In electrical water-heating apparatus, in combination, a main casingadapted to form a path of flow for water therethrough, a valve mountedin said casing and adapted to control the flow of water therethrough; acylindrical housing detachably connected with said main casing andadapted to form a continued path of flow for water; and an electricheating-unit mounted within said cylindrical casing, and comprising ahollow cylindrical core of lesser outside diameter than the insidediameter of said housing, having a resistance element disposed upon itsinterior and exterior cylindrical surfaces.

24. In electrical water-heating apparatus, in combination, asubstantially cylindrical casing having an inlet passage substantiallyat its upper end; an electric heating-unit comprising a resistanceelement mounted adjacent to the interior walls of said casing, andadapted to heat water passing downwardly through said casing; a tubesubstantially centrally positioned within said cylindrical casing, andhaving a connection at its lower end, with the path of flow formed bysaid casing, and a discharge passage connnected with the upper end ofsaid tube.

In electrical waterheating apparatus. in combination, a substantiallycylindrical main casing, having an inlet passage at its upper end, anelectric heating-unit mounted within said casing and comprising a hollowcylindrical core. having a resistance element disposed upon its interiorand exterior surfaces, said core having a lesser outside diameter thanthe inside diameter of said cylindrical casing, thereby to form aplurality of paths of flow in a downward direction through said casing;a conduit, substantially centrally positioned within said cylindricalcasing. and within said core, and having a connection at its lower endwith said plu rality of paths of flow, formed by said core in saidcasing; and a discharge outlet connected with the upper end of saidconduit.

26. In electrical water-heating apparatus, in combination, a casingadapted to form a path of flow for water there-through: means forming anenclosed housing extending substantially transversely through saidcasing: an electric heating-unit mounted within said casing and adaptedto heat water passing therethrough: a switch mounted within saidenclosed housing for controlling the current to said heating-unit aconduit extending through said enclosed housing for completing the pathof flow through said casing, and a valve associated with said conduitfor controlling the flow of water therethrough.

27. In electrical water-heating apparatus. in combination, a casing madeup of a plurality of sections and adapted to provide a path of flow forwater, two adjacent sections being substantially concentric and the onerotatable with respect to the other, an electric heating unit withinsaid casing, a valve for controlling the flow of water past said heatingunit, a switch for controlling All) the How of current to said heatingunit, means responsive to a rotary movement in one direction of saidrotatable section of said casing for operating either said valve andsaid switch substantially conjointly or said valve alone in accordancewith the presence or absence of Water in said path of flow,respectively, and responsive to a rotary movement of said section in thereverse direction for restoring either said valve and 10 7 name to thisspecification this 2&th day of 15 January 1922. V

ALAN VARLEY LIVINGSTON.

